System and method to radially constrict a stent graft

ABSTRACT

A stent graft system including a component having longitudinally extending outer surface and inner surface, the inner surface defining a lumen having a longitudinal axis, a plurality of stents distributed longitudinally along the component, and a plurality of suture loops, each suture loop attached to the inner outer surface, of the stent graft, a first suture loop spaced laterally and longitudinally relative to an adjacent suture loop when the component is in an expanded configuration, the plurality of suture loops aligned longitudinally along the stent graft when the stent graft is in a radially constricted configuration, at least one ligature having a proximal end and a distal end, the ligature extending through at least some of the plurality of suture loops, whereby tension on the at least one ligature longitudinally aligns the suture loops along the longitudinal axis of the component, thereby at least partially radially constricting the stent graft.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/379,490, filed on Apr. 9, 2019, which was a continuation ofInternational Application No. PCT/US2018/019344, which designated theUnited States and was filed on Feb. 23, 2018, published in English,which claims the benefit of U.S. Provisional Application No. 62/463,031,filed on Feb. 24, 2017. The entire teachings of the above applicationsare incorporated herein by reference.

BACKGROUND

Aortic pathologies, including aortic aneurysms, can be treated by opensurgical reconstruction, or alternatively, endovascular repair, which isa minimally invasive alternative to open surgical repair. Optimizing asuccessful outcome of endovascular repair, however, requires assessmentof the patient's anatomy and, in the case of an aortic aneurysm, anappropriate stent graft that spans the proximal and distal ends of theaneurysm to insure complete exclusion of the aneurysm sac, anchoring ofthe stent graft in the aorta, and minimal endoleaks. Also, endoleaks andpost-surgical enlargement of the aneurysm can require additional repairto seal any expansion of the aneurysm sac, and, generally, must be donewithout significantly compromising blood flow through the surgical siteto surrounding viscera and associated structures.

Therefore, a need exists for new and improved delivery devices,endovascular repair devices for implanting stent grafts, and methods oftheir use, to treat aortic pathologies, in particular aortic aneurysms.

SUMMARY

The present invention relates to stent graft systems for use in treatingand repairing aortic vascular damage, such as vascular damage associatedwith aortic aneurysms, for example, in regions of the aorta havingarterial branches to vital organs and tissues, such as, thoracic aorticaneurysms, abdominal aortic aneurysms, and thoracoabdominal aorticaneurysms, including juxtarenal aortic aneurysms and short-neckabdominal aortic aneurysms.

In one embodiment, the invention is a stent graft system that includes astent graft having a luminal and flexible graft component defining aproximal open end, a distal open end, and having an outside surface andinside surface extending from the proximal open end to the distal openend, the inside surface defining a lumen having a longitudinal axis. Thestent graft also includes a plurality of stents distributedlongitudinally along the luminal flexible graft component and aplurality of suture loops spaced radially and longitudinally along theluminal flexible graft component in an arrangement that causes the stentgraft to be in a radially constricted position when the suture loops aresubstantially aligned along the longitudinal axis of the stent graft.The stent graft system also includes at least one ligature having aproximal end and a distal end. The at least one ligature extends throughthe suture loops, wherein tension on the ligature or stiffness of theligature substantially aligns the suture loops, thereby at leastpartially radially constricting the stent graft.

In another embodiment of the invention, a stent graft is delivered to ananeurysm site of a subject by a method that includes directing a stentgraft to an aneurysm site by maintaining at least one of a plurality ofstents of the stent graft in a constricted position with a ligatureextending through a plurality of suture loops spaced longitudinallyalong a flexible luminal graft component, a luminal flexible graftcomponent including a proximal open end, a distal open end, and outsideand inside surfaces of the luminal wall extending from the proximal openend to the distal open end. The stent graft is released from theconstricted position by movement of the ligature relative to the sutureloops, thereby implanting the stent graft at the aneurysm site of thesubject.

This invention has many advantages. For example, the physician canrotate the stent graft after it has been partially deployed, such as byonly partially removing the radial constraint, or withdrawing only aportion of a plurality of radial restraints. Further, in certainembodiments, tension on a flexible ligature reversibly aligns the sutureloops to thereby reversibly and radially collapse the stent graft. As aconsequence, the stent graft system of the invention provides greatercontrol relative to delivery systems that are only able to align a stentgraft prior to full radial expansion of a stent graft. Accordingly, astent graft can be deployed at a surgical site with more accuracy, lessrisk of injury to the vasculature of the subject, and withoutsignificant risk of distorting the intended shape of the stent graftwhen implanted at the surgical site.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of example embodiments, as illustrated in the accompanyingdrawings in which like reference characters refer to the same partsthroughout the different views. The drawings are not necessarily toscale, emphasis instead being placed upon illustrating embodiments. Thesame number present in different figures represents the same item.

FIG. 1A is a perspective view of a stent graft system of the invention,wherein a ligature extends through suture loops at an outside surface ofa stent graft.

FIG. 1B is a perspective view of the stent graft system shown in FIG.1A, but wherein the ligature is under tension, thereby causing the stentgraft to be in a constricted position.

FIG. 2 is a perspective view of another embodiment of a stent graftsystem of the invention, wherein a ligature extends through suture loopsat an inside surface of a stent graft.

FIG. 3A is a perspective view of still another embodiment of a stentgraft system of the invention, wherein two ligatures extend throughseparate sets of suture loops distributed at proximal and distalportions of a stent graft.

FIG. 3B is a perspective view of the stent graft system of FIG. 3A,wherein a ligature threading suture loops at a proximal portion of thestent graft is under tension, while a ligature threading suture loops ata distal portion of the stent graft is in a relaxed position.

FIG. 3C is a perspective view of the stent graft system of FIGS. 3A and3B, wherein the ligature threading suture loops at the proximal portionof the stent graft is in a relaxed position while the ligaturesthreading suture loops at the distal portion is under tension.

FIG. 4A is a perspective view of a yet another embodiment of the stentgraft system of the invention, wherein the ligature is a wire that issufficiently rigid to maintain a proximal portion of the stent graftprosthesis in a constricted position when the wire extends throughsuture loops at an outside surface of the stent graft, without requiringthat the wire be under tension.

FIG. 4B is a perspective view of the stent graft system shown in FIG.4A, wherein the wire has been partially retracted from the suture loopsat the proximal end of the stent graft, thereby partially releasing thestent graft from radial constriction.

FIG. 4C is a perspective view of the stent graft system of FIGS. 4A and4B, following complete retraction of the wire from the suture loopsradially constricting the stent graft.

FIG. 5A is a perspective view of still another embodiment of a stentgraft system of the invention, wherein two wires extend through separatesets of suture loops, one set of suture loops being at a proximalportion of the stent graft, and the other at a distal portion of thestent graft, thereby radially constricting the stent graft.

FIG. 5B is a perspective view of the stent graft system of theinvention, wherein the wire extending through the set of suture loops atthe distal portion of the stent graft has been removed, whereby thedistal portion of the stent graft is released from radial constriction.

FIG. 5C is a perspective view of the stent graft prosthesis of FIGS. 5Aand 5B, wherein the wire extending through the set of suture loops atthe proximal portion of the stent graft has been removed, whereby theproximal portion of the stent graft is released from radialconstriction.

FIG. 6A is a perspective view of another embodiment of a stent graftsystem of the invention, wherein three ligatures extend through separatesets of suture loops distributed at the proximal portion of a stentgraft.

FIG. 6A(i) is a schematic representation of a cross section of a detailof the stent graft system of FIG. 6A taken along line 6A(i)-6A(i).

FIG. 6B is a perspective view of the stent graft system of FIG. 6A,wherein the ligatures threading suture loops at a proximal portion ofthe stent graft are under tension, thereby causing the proximal portionof the stent graft to be in a constricted position.

FIG. 6B(i) is a schematic representation of a cross section of a detailof the stent graft system of FIG. 6B taken along line 6B(i)-6B(i).

FIG. 7 is an exploded side view of yet another embodiment of a stentgraft system of the invention.

FIG. 8A is an assembled view of the stent graft system shown in FIG. 7 ,wherein the stent graft shown in FIG. 7 has been loaded within anintroducer sheath component of the stent graft system and, therefore, isnot shown.

FIG. 8B is a side view of the stent graft system shown in FIG. 8Afollowing direction of the stent graft to an aneurysm site of a subjectin a constricted position, and following retraction of the introducersheath of the stent graft system in a proximal direction to expose thestent graft, which is maintained in a constricted position by tension onthe ligature.

FIG. 8C is a side view of the stent graft system shown in FIGS. 8A and8B following retraction of one of two wires from suture loopsdistributed along a portion of the stent graft, thereby releasing theproximal portion of the stent graft from radial constriction.

FIG. 8D is a side view of the stent graft system shown in FIGS. 8A-8Cfollowing retraction of the other of the two wires from suture loops, ata distal portion of the stent graft, thereby releasing the distalportion of the stent graft from radial constriction.

FIG. 8E is a side view of the stent graft system shown in FIGS. 8A-8Dfollowing proximal retraction of both wires from the stent graft,thereby causing release from radial constriction along the entirety ofthe stent graft and completing delivery of the stent graft at theaneurysm site.

FIG. 8F is a side view of the stent graft system of the invention shownin FIGS. 8A-8E, following retraction of remaining portions of the stentgraft system, not implanted at the aneurysm site, from the aneurysm siteof the subject.

FIG. 9 is an exploded side view of another stent graft system of theinvention, wherein flexible ligatures are employed rather than thesemi-rigid wires of the embodiment shown in FIGS. 7 and 8A-8F.

FIG. 10A is an assembled view of the stent graft system shown in FIG. 9, wherein the stent graft shown in FIG. 9 has been loaded within anintroducer sheath component of the stent graft system and, therefore, isnot shown.

FIG. 10B is a side view of the stent graft system shown in FIG. 10Afollowing direction of the stent graft to an aneurysm site of a subjectand following retraction of the introducer sheath of the stent graftsystem in a proximal direction to expose the stent graft, which ismaintained in a constricted position by tension on the flexibleligatures.

FIG. 10C is a side view of the stent graft system shown in FIGS. 10A and10B, wherein the tension on a flexible ligature constricting a proximalportion of the stent graft has been relaxed, thereby causing theproximal portion of the stent graft to radially expand.

FIG. 10D is a side view of the stent graft delivery system shown inFIGS. 10A-10C, wherein tension has been reapplied to the flexibleligature, thereby constricting the proximal portion of the stent graft,and the flexible ligature constricting a distal portion of the stentgraft has been released, thereby causing the distal portion of the stentgraft to radially expand from a constricted position to an expandedposition.

FIG. 10E is a side view of the stent graft system shown in FIGS.10A-10D, wherein the flexible ligature at both the proximal and distalportions of the stent graft have been relaxed, thereby causing theentirety of the stent graft to radially expand from a constrictedposition to an expanded position.

FIG. 10F is a side view of the stent graft system of FIGS. 10A-10E,wherein the flexible ligatures have been released at their respectivedistal ends, and withdrawn from the sutures of the stent graftcompleting delivery of the stent graft at the aneurysm site, and whereinthe remainder of the stent graft delivery system not implanted has beenretracted from the aneurysm site.

DETAILED DESCRIPTION

The invention is generally directed to stent graft systems for use intreating and repairing aortic vascular damage, such as vascular damageassociated with arterial aneurysms in, for example, regions of the aortahaving arterial branches to vital organs and tissues, such as thoracicaortic aneurysms, abdominal aortic aneurysms and thoracoabdominal aorticaneurysms, including a juxtarenal aortic aneurysms and short-neckabdominal aortic aneurysms. The same number in different figuresrepresents the same item.

The features and other details of the invention, either as steps of theinvention or as combinations of parts of the invention will now be moreparticularly described and pointed out in the claims. It will beunderstood that the particular embodiments of the invention are shown byway of illustration and not as limitations of the invention. Theprinciple features of this invention can be employed in variousembodiments without departing from the scope of the invention.

A description of example embodiments of the invention follows.

When reference is made herein to a prosthesis, also referred to hereinas “vascular prosthesis,” “stent graft,” or “stent graft prosthesis,” tobe delivered, or implanted in a patient, the word “proximal” means thatportion of the prosthesis or component of the prosthesis that isrelatively close to the heart of the patient and “distal” means thatportion of the prosthesis or component of the prosthesis that isrelatively far from the heart of the patient. A “longitudinal axis,” asthat term is defined herein, means an axis along a lengthwise directionof a body that also passes through a center of gravity of the body.

When, however, reference is made to a delivery system or a component ofa delivery system employed to deliver, or implant, a prosthesis, theword, “proximal,” as employed herein, means closer to the clinicianusing the delivery system. When reference is made to a delivery systemor a component of a delivery system, “distal,” as that term is employedherein, means, further away from the clinician using the deliverysystem.

For clarity, the word “proximate” means “close to,” as opposed to themeanings ascribed to “proximal” or “distal” described above with respectto either the prosthesis or a delivery system.

One embodiment of a stent graft system of the invention is shown in FIG.1A. As shown therein, stent graft system 10 includes stent graft 12.Stent graft 12 includes luminal flexible graft component 14 definingproximal open end 16 and distal open end 18. Luminal flexible graftcomponent 14 also includes outside surface 20 and inside surface 22extending from proximal open end 16 to distal open end 18. Insidesurface 22 defines a lumen having longitudinal axis 26. Bare stent 24 isat proximal open end 16 of luminal flexible graft component 14. Aplurality of stents 28 are distributed longitudinally along outsidesurface 20 of flexible luminal graft component 14. Stents 28 includestruts 30 that define proximal apices 32 and distal apices 34, and arefixed to outside surface 20 by a suitable method, such as is known inthe art, such as by use of suture thread to sew stents 28 to luminalflexible graft component.

Ligature 42 extends through suture loops 36 in longitudinal sequencealong longitudinal axis 26. Stabilizing suture loop 41 is located atdistal portion 40 of luminal flexible graft component 14 to stabilizeligature 42 along flexible luminal graft component 14. Ligature 42includes proximal end 44 and distal end 46. In an embodiment, at least aportion of suture loops are between an opening of struts of a stent,referred to herein as “nested,” as shown in FIG. 1A.

Ligature suture loops 36 are distributed along proximal portion 38 ofluminal flexible graft component 14 and are distributed laterally andlongitudinally relative to each other in an arrangement that causes thestent graft to be in a radially constricted position when suture loops36 are substantially longitudinally aligned, thereby at least partiallyradially constricting stent graft 12, as shown in FIG. 1B. When ligature42 is under longitudinal tension, suture loops 36 align along stentgraft 12, thereby causing stents 28 and luminal flexible graft component14 at proximal portion 38 to selectively partially radially collapseinto a radially constricted position. Tension can be applied to ligature42 by retraction of proximal end 44 by the surgeon in the directionindicated by proximal arrow 48, while distal end 46 is fixed to anothercomponent of delivery system 10, such as a nose cone (not shown).Release of tension on ligature 42 causes stents 28 to return proximalportion 38 to a radially expanded position, shown in FIG. 1A. Bare stent24 and stents 28 are formed of a suitable material, such as is known inthe art. Examples of suitable materials include stainless steel and ashape memory alloy, such as nitinol. When formed of a shape memoryalloy, or certain other suitable materials, stent 28 can radiallyself-expand upon release from constriction by ligature 42 extendingthrough suture loops 36. In embodiments where stents 28 are not radiallyself-expanding once released from radial constriction, stents 28 can beradially expanded by, for example, a balloon catheter (not shown), suchas is known in the art.

Luminal flexible graft component 14 is formed of a suitable material,such as is known in the art. Examples of such materials include at leastone member selected from the group consisting of polytetrafluoroethylene(PTFE), such as expanded (ePTFE), and polyethylene terephthalate (PET),such as woven polyester. Suture loops 36 are fabricated of a suitablematerial, such as is known in the art, including, for example polyester,nylon and polypropylene. Ligature 42 is sufficiently flexible to allowstents 28, when radially self-expanding, to radially expand in theabsence of longitudinal tension on ligature 42. Examples of materialsuitable for use in ligature are known to those skilled in the art, suchas wire, thread and cords.

In another embodiment, shown in FIG. 2 , stent graft system includesligature and sutures at inside surface 22 of stent graft 12, rather thanoutside surface 20, as shown in FIGS. 1A and 1B. In this embodiment,stent graft system 60 is like that of stent graft system 10, butincludes ligature 62, respective suture loops 64, and stabilizing loop65 through which ligature 62 is threaded, at inside surface 22 ofluminal flexible graft component 14. As with stent graft system 10 ofFIGS. 1A and 1B, radial constriction and expansion of stent graft 66 ofstent graft system 60 of FIG. 2 can be achieved by applying and relaxingtension on proximal end 68 of ligature 62 while distal end 69 ofligature 62 is fixed to another component of stent graft system 60, suchas a nose cone, not shown.

It is to be understood that additional ligatures (not shown) can beemployed, along with additional distinct sets of suture loopsdistributed longitudinally along luminal flexible graft component. Forexample, the stent graft system of the invention can include threeligatures, as shown in FIGS. 6A through 6B, described below, or fourligatures (not shown). The stent graft can optionally include at leastone fenestration. It is to be further understood that, in otherembodiments, ligatures can, each, independently, be within or outside ofluminal flexible graft component 14, and, correspondingly threadedthrough sets of suture loops that are at either outside surface 20 orinside surface 22 of luminal flexible graft component 14.

For example, in another alternative embodiment, shown in FIG. 3A, stentgraft system 70 includes two ligatures 72,74, each of which is threadedthrough a separate set of suture loops 76,78, respectively, distributedalong outside surface 20 of luminal flexible graft component 14. In thisembodiment, ligature 72 extends through set of suture loops 76predominantly distributed at proximal portion 38 of luminal flexiblegraft component 14, while ligature 74 extends through set of sutureloops 78 distributed predominantly at distal portion 40 of luminalflexible graft component 14. Stabilizing loop 73 for ligature 72 is atdistal portion 40 of flexible luminal graft component 14, whilestabilizing loop 75 for ligature 74 is at proximal portion 38 offlexible luminal graft component 14.

The embodiment shown in FIGS. 3A and 3B enables selective variableconstriction of proximal portion 38 and distal portion 40 of luminalflexible graft component 14 by selectively and independently applyingtension to ligatures 72,74 at proximal ends 80,84 of ligatures 72,74,respectively, in a proximal direction indicated by arrow 88, whiledistal ends 82,86 of ligatures 72,74, respectively, are fixed to anothercomponent of stent graft system 70, such as a nose cone (not shown).Specifically, as can be seen in FIG. 3B, ligature 72 is under tension,while ligature 74 is not under tension, thereby causing selective radialconstriction of proximal portion 38 of luminal flexible graft component14 by forcing longitudinal alignment of proximal suture loops 76.Conversely, and as shown in FIG. 3C, ligature 74 is under tension, whileligature 72 is not under tension, thereby causing luminal flexible graftcomponent to be selectively radially constricted at distal portion 40 ofluminal flexible graft component 14 by forced alignment of distal sutureloops 78.

In yet another embodiment, shown in FIGS. 4A-4C stent graft system 90includes stent graft 91. Ligature 92 is sufficiently rigid to causesuture loops 94 to be substantially longitudinally aligned alongflexible luminal graft component 93 of stent graft 91 when suture loops94 are threaded by ligature 92, thereby radially constricting stentgraft 91. Stabilizing loop 100 is distal to suture loops 94. An exampleof a suitable ligature in this embodiment is a wire, for example,materials known to those skilled in the art, such as stainless steel ora shape memory alloy, such as nitinol. As can be seen in FIG. 4B,partial retraction of ligature 92 in a proximal direction indicated byarrow 96 toward the surgeon causes ligature 92 to be retracted from aset of suture loops 94, thereby causing stents 28 proximate to thosesuture loops to expand from a constricted position to an expandedposition, as shown at portion 102 of stent graft 91. Progressiveretraction of ligature 92 causes progressive expansion of stents 28 ofstent graft 91 from constricted positions to radially expandedpositions, accordingly, from proximal end 98 of stent graft 91progressively through to most-distal suture loop 95, that issufficiently proximate to another of suture loops 94 to cause at leastpartial radial collapse of stents 28 when threaded by ligature 92.Complete retraction of ligature 92 from suture loops 94 causes expansionof stent graft 91 from a constricted position to an expanded position,as shown in FIG. 4C.

In another embodiment, shown in FIGS. 5A-5C, stent graft system 110includes stent graft 112, and two ligatures 114,116 extending throughproximal set of suture loops 118 and distal set of suture loops 120, andstabilizing loops 115,113, respectively. As shown in FIG. 5A, stentgraft 112 is held in a constricted position along its length byligatures, such as wires 114,116, extending through proximal and distalsets of suture loops 118,120 distributed predominately at proximalportion 122 and distal portion 124 of stent graft 112, respectively.Ligatures, as shown in FIG. 5A, are wires 114,116, that are sufficientlyrigid to constrict stents 28 at proximal set of suture loops 118 anddistal set of suture loops 120 threaded by wires 114,116. Selectiverelease of constriction of proximal portion 122 and distal portion 124of stent graft 112 by independent and selective retraction of wires114,116 from proximal set of suture loops 118 or distal set of sutureloops 120 through which they are threaded. It is to be understood that,ligatures can, independently, be flexible or rigid, or within or outsideof stent graft 112, thereby enabling selective constriction or releaseof proximal portion 122 and distal portion 124 of stent graft 112, as inis shown in FIGS. 5B and 5C.

Another embodiment of a stent graft system of the invention is shown inFIGS. 6A and 6B. As shown therein, stent graft system 10 of FIG. 1 hasbeen modified to stent graft system 10 a, and includes three ligatures42, 42 a, and 42 b that each extend through separate sets of sutureloops 36, 36 a, and 36 b distributed at stent graft 12 a at proximalportion 38 of stent graft 12 a. In an embodiment, stent graft 12 aincludes fenestration 31 (FIG. 6A(i) and FIG. 6B(i)). Ligature sutureloops 36, 36 a, and 36 b are distributed along proximal portion 38 ofluminal flexible graft component 14 and are distributed radially,laterally and longitudinally relative to each other in an arrangement,as shown in FIG. 6A, and schematically represented in the cross sectionshown in FIG. 6A(i) taken along line 6A(i)-6A(i) of FIG. 6A. Alignmentof ligature suture loops 36, 36 a, and 36 b, such as by applying tensionon each of ligatures 42, 42 a, and 42 b, by moving the proximal ends 44,44 a, and 44 b in the direction of arrow 48, while distal ends 46, 46 a,and 46 b are secured relative to the remainder of stent graft system 10a. Under tension, stent suture loops 36, 36 a, 36 b of each respectiveligature 42, 42 a, and 42 b become relatively longitudinally aligned,thereby at least partially radially constricting a proximal portion 38of luminal graft component 14, as shown in FIG. 6B, and as schematicallyrepresented in the cross section shown in FIG. 6B(i), taken along line6B(i)-6B(i) of FIG. 6B. It is to be understood that other arrangementsof ligatures about stent graft 12 a are also possible, such as whereinstead of three ligatures, along with a fenestration, being evenlydistributed about the flexible luminal graft material, only twoligatures may be present and evenly distributed, or only a singleligature or a plurality of ligatures may be present, but unevenlydistributed, or variously distributed longitudinally along the stentgraft.

FIG. 7 is an exploded side view of another embodiment of a stent graftsystem of the invention. As shown therein, stent graft system 130 hasguidewire catheter 132 that includes proximal end 134 and distal end136. Nose cone 137 is fixed to distal end 136 of guidewire catheter 132,while proximal handle 138 is fixed to proximal end 134 of guidewirecatheter 132. Wires 140,142 each include distal end 144,146 and proximalend 148,150, respectively. Wire handles 152,154 are fixed at proximalends 148,150 of wires 140,142, respectively. Stent graft 156 includesproximal end 158, distal end 160, stents 162, proximal bare stent 164,and proximal and distal sets of suture loops 166,168 of luminal graftcomponent 170 of stent graft 176. In an embodiment, stent graft 176includes at least one fenestration 171. Fenestration 171 is defined byluminal graft component 170. Introducer sheath 172 includes distal end174 and proximal end 176. Distal handle 178 is fixed at proximal end 156of introducer sheath 170. Wires 140,142 are sufficiently stiff toconstrict the radial diameter of stent graft 156 by longitudinallyaligning component suture loops of each set of suture loops 166,168without wires 140,142 being under tension.

FIG. 8A is a side view of the embodiment of a stent graft system 130shown in FIG. 7 , but in assembled form, wherein distal ends 144,146 ofligatures 140,142 have been threaded through proximal set of sutureloops 166 and distal set of suture loops 168, respectively, at stentgraft 156, and wherein stent graft 156 has been loaded within introducersheath 172.

In one embodiment of a method of the invention, and as shown in thetransition from FIG. 8A to FIG. 8B, stent graft system 130 is directedthrough an artery of a subject to aneurysm site 180 of the artery, andstent graft 156 is located at and spans aneurysm site 180, havingarterial branch 181, as shown. In the embodiment shown, stent graft 156is exposed by retraction of distal handle 178, in the direction of arrow182, thereby retracting introducer sheath 172 from stent graft 156,which is held in a radially constricted position by wires 140,142. It isto be understood that, in an alternative embodiment, not shown, stentgraft 156, in a radially constricted position, can be directed toaneurysm site 180 by advancement of proximal handle 138 toward distalhandle 178, and thereby directing stent graft 156 from within introducersheath 172 to aneurysm site 180 in the direction indicated by arrow 184to thereby span aneurysm site 180.

FIG. 8C is a side view of stent graft system 130 shown in FIGS. 8A and8B, wherein the wire 140, having sufficient rigidity to constrainproximal set of suture loops 166 at proximal portion 158 of prosthesis156 without being under tension, has been retracted by retraction ofwire handle 152 in the direction indicated by arrow 182, therebyallowing stents 162 at proximal portion 158 of stent graft 156 and,therefore, proximal portion 158 of stent graft 156, to radially expand.As described above, where stents 156 are self-expanding, such asself-expanding stents formed of nitinol, withdrawal of wire 140 willcause stent 156 and, consequently, proximal portion 158 of stent graft156 to selectively radially expand from the constricted direction to anexpanded diameter without assistance, such as by use of a ballooncatheter.

Alternatively, as shown in FIG. 8D, wire 142, has sufficient rigidity tomaintain radially constricted distal portion 168 of stent graft 156 bymaintaining distal set of suture loops 168 in a longitudinally alignedposition and, therefore, maintain stents 162 at distal portion 160 ofstent graft 156 in a radially constricted position. Wire handle 154 isretracted, in the direction indicated by arrow 182, from the positionshown in FIG. 8B to that shown in FIG. 8D, while wire handle 152 andwire 140 remain in the position shown in FIG. 8B. As a result, wire 142is retracted from distal set of suture loops 168, thereby causing stentsof stent graft 156 at distal portion 160 of stent graft 156 to radiallyexpand from the constricted position to a radially expanded position,such as by employing radially self-expanding stents or some othertechnique known in the art, such as use of a balloon catheter (notshown).

FIG. 8E shows stent graft 156 in a radially expanded position, followingretraction of both wires 140,142 as a step subsequent to any of therepresentations shown in FIGS. 8B, 8C, and 8D. Bare stent 164, shown inFIG. 8E, has been released from apex capture device 190 at distal end ofguidewire catheter. FIG. 8F is a side view of the stent graft system 130following full implantation of stent graft 156 at aneurysm 180including, depending on the presence of arterial branch 181,implantation of branch prosthesis 183, and retraction of the remainderof the stent graft system 130 from aneurysm site 180 and from thesubject.

FIG. 9 is an exploded side view of still another embodiment of a stentgraft system of the invention. As shown therein, stent graft system 200has guidewire catheter 202 that includes distal end 204 and proximal end206. Nose cone 208 is fixed to distal end 204 of guidewire catheter 202.Proximal handle 210 is fixed to proximal end 206 of guidewire catheter.Ligatures are flexible threads 212,214 each having a distal end 216,218and proximal end 220,222, and wherein control handles 224,226 are fixedto proximal end 220,222 of each thread 212,214, respectively. Stentgraft 228 includes proximal portion 230 and distal portion 232. Proximalsuture loops 234 and distal suture loops 236 are distributedpredominately at proximal portion 230 and distal portion 232 of stentgraft 228, respectively. Stents 227 are distributed longitudinally alongstent graft 228. Optionally, stent graft 228 defines fenestration 229.Bare stent 252 extends proximally from proximal portion 230. Introducersheath 238 includes distal end 240 and proximal end 242. Distal handle244 is fixed to proximal end 242 of introducer sheath 238.

FIG. 10A is a side view of the embodiment of stent graft system 200shown in FIG. 8 , in assembled form. Threads 212,214 extend throughrespective proximal suture loops 234 and suture loops 236 at stent graft228 and are fixed at distal end 204 (not shown in FIG. 10A) of guidewirecatheter 202. Stent graft 228 (not shown in FIG. 10A) is loaded withinintroducer sheath 238 and threads 212,214 are held in tension, therebycausing each of proximal suture loops 234 and distal suture loops 236 tobe held in an arrangement that constricts the radial diameter of stentgraft 228.

In a method of the invention, stent graft system 200 is deliveredthrough an artery to aneurysm site 246 having arterial branch 245. Stentgraft 228 spans aneurysm site 246, as shown in FIG. 10B. Introducersheath 238 is then retracted by directing distal handle 244 in aproximal direction, shown by arrow 248, toward the surgeon, therebyexposing stent graft 228, that is held in a radially constrictedposition by tension on threads 212,214. It is to be understood that, inan alternative embodiment of the method of the invention, proximalhandle 210 can be advanced toward distal handle 244 in a distaldirection indicated by arrow 250 to thereby direct stent graft 228,while in a radially constricted position, from distal end 240 ofintroducer sheath 238 and through an artery to aneurysm site 246 tothereby radially span aneurysm site 250.

In one embodiment of the method, control handle 224 is advanced indistal direction 250, from proximal handle 210 to distal handle 242, asshown in the transition from FIG. 10B to FIG. 10C, to thereby relaxthread 212, thereby allowing radially self-expanding stents 227 (orballoon catheter, not shown, within stents 227, as appropriate) atproximal portion 230 of stent graft 228 to radially expand from aconstricted position to an expanded position. Alternatively, as shown inthe transition from FIG. 10B to FIG. 10D, control handle 224 can remainin a proximal position (FIG. 10B), and control handle 226 can bedirected in a proximal direction indicated by arrow 248 to thereby relaxthread 214 constraining stents 227 at distal portion 232 of stent graft228, whereby radially self-expanding stents 227 at distal portion 232 ofstent graft 228 radially expand from a constricted position, shown inFIG. 10B, to a radially expanded position, shown in FIG. 10D.

Similarly, as shown in the transition from FIG. 10B to 10E, controlhandles 224,226 can both be advanced in the direction of arrow 250,thereby relaxing tension on both corresponding threads 212,214, therebycausing proximal suture loops 234 and distal suture loops 236 to relaxradial constraint on radially self-expanding stents at both proximalportion 230 and distal portion 232 of stent graft 228, thereby allowingthe entirety of stent graft 228 to radially expand from a constrictedposition, shown in FIG. 10B, to radially expanded position, shown inFIG. 10E. It is to be understood that, in the embodiment represented inFIGS. 10A through 10E, each of the configurations shown can follow orprecede any of the other configurations or any configuration in between,due to the radially self-expanding nature of the stents of theprosthesis (or that of a balloon catheter, or catheters), if they areemployed simultaneously with release of stent graft 228 from radialconstriction by relaxation are increased of tension on either or both ofthreads 212,214. This variability enables fine adjustment of stent graft228 at aneurysm site 246 before it is released from threads 212,214 andguidewire catheter 202.

As shown in the transition from FIG. 10E to FIG. 10F, following rotationand axial alignment of fenestration 229 with branch artery 245, asappropriate or necessary, bare stent 252 is released from capture atnose cone 208 by apex capture device 254, such as is known in the art.Threads 212,214 are then severed from guidewire catheter 202 or nosecone 208 and distal ends 216,218 of threads, by a suitable mechanism,such as by rotating proximal handle 242 and, therefore, guidewirecatheter 202 and nose cone 208 relative to control handles 224,226 tothereby sever distal ends 216,218 of threads 212,214 with blades (notshown) integrated within distal end 204 of guidewire catheter 202 ornose cone 208. At this point, stent graft 228 is fully implanted ataneurysm site 246 including, depending on the presence of arterialbranch 245, implantation of branch prosthesis 247, as necessary orappropriate, spanning fenestration 229 and branch artery 245, and theremainder of stent graft system 200 that has been severed from stentgraft 228 can be retracted from aneurysm site 246 and the patient, asshown in FIG. 10F.

It is also to be understood that, as with the embodiments shown in FIGS.7 and 8A-8F, threads and wires can be employed in combination, andadditional wires with threads can be employed to further improverefinement of control over various portions of the stent graft, such asby employing a third wire, thereby enabling independent control overradial expansion of separate proximal, middle, and distal portions of astent graft.

Further, stent graft can include a fenestration in the embodiments ofthe method wherein the stent graft is to be placed at an aneurysmspanning a branch artery. Also, it is to be understood, that asdescribed in earlier embodiments, a ligature, whether wires or threadsof the embodiment shown in FIGS. 8, 9A-9F, and 10A-10F can be arranged,independently of each other, to extend within stent graft or outsidesurface of stent graft.

Vascular prostheses implanted by the stent graft systems and methods ofthe invention can be implanted, for example, by transfemoral access.Additional branch prostheses that are directed into the vascularprostheses of the invention can be implanted, for example, bysupraaortic vessel access (e.g., through the brachial artery), or bytransfemoral access, or access from some other branch or branch of majorblood vessels, including peripheral blood vessels.

The teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety. Therelevant teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety. Therelevant teachings of U.S. Pat. Nos. 8,292,943; 7,763,063; 8,308,790;8,070,790; 8,740,963; 8,007,605; 9,320,631; 8,062,349; 9,198,786;8,062,345; 9,561,124; 9,173,755; 8,449,595; 8,636,788; 9,333,104;9,408,734; 9,408,735; 8,500,792; 9,220,617; 9,364,314; 9,101,506;8,998,970; 9,554,929; 9,439,751; 9,592,112; 9,655,712, 9,827,123,9,877,857, 9,907,686; U.S. patent application Ser. Nos. 14/575,673;15/166,818; 15/167,055; 14/272,818; 14/861,479; 15/478,424; 15/478,737;15/587,664; 15/604,032; 15/672,404; 15/816,772; 15/839,272; 15/417,467;PCT/US2017/025844; PCT/US2017/025849; PCT/US2017/025912;PCT/US2017/034223 and PCT/US2017/046062, are also incorporated byreference in their entirety.

The relevant teachings of the “Delivery System For Radially Constrictinga Stent Graft and Method of Use,” by Eduardo Alejandro Garcia,International Application No. PCT/US2018/019355, filed on Feb. 23, 2018;“Delivery System and Method to Radially Constrict a Stent Graft,” byTimothy Lostetter, International Application No. PCT/US2018/019349,filed on Feb. 23, 2018; “Vascular Prosthesis with MoveableFenestration,” by Samuel Arbefeuille, International Application No.PCT/US2018/019353, filed on Feb. 23, 2018; “Stent Graft Delivery Systemwith Constricted Sheath and Method of Use,” by Timothy Lostetter,International Application No. PCT/US2018/019354, filed on Feb. 23, 2018;“Stent Graft with Fenestration Lock,” by Timothy Lostetter,International Application No. PCT/US2018/019352, filed on Feb. 23, 2018;“Constrainable Stent Graft, Delivery System and Methods of Use,” bySamuel Arbefeuille and Nico Bahar, International Application No.PCT/US2018/019342, filed on Feb. 23, 2018; “Vascular Prosthesis withCrimped Adapter and Methods of Use,” by Samuel Arbefeuille,International Application No. PCT/US2018/019350, filed on Feb. 23, 2018;“Radially Adjustable Stent Graft Delivery System,” by SamuelArbefeuille, Eduardo Alejandro Garcia and Scott L. Rush, InternationalApplication No. PCT/US2018/019356, filed on Feb. 23, 2018; “VascularProsthesis with Fenestration Ring and Methods of Use,” by TimothyLostetter, International Application No. PCT/US2018/019351, filed onFeb. 23, 2018; “Distal Torque Component, Delivery System and Method ofUsing Same,” by Samuel Arbefeuille, International Application No.PCT/US2018/019510, filed on Feb. 23, 2018, are also incorporated byreference in their entirety.

While example embodiments have been particularly shown and described, itwill be understood by those skilled in the art that various changes inform and details may be made therein without departing from the scope ofthe embodiments encompassed by the appended claims.

1. A stent graft system, comprising: a) a stent graft that includes i) acomponent having longitudinally extending outer surface and alongitudinally extending inner surface, the inner surface defining alumen having a longitudinal axis, ii) a plurality of stents distributedlongitudinally along the component, and iii) a plurality of sutureloops, 1) each suture loop attached to the inner surface, or outersurface, of the stent graft, 2) a first suture loop spaced bothlaterally and longitudinally relative to an adjacent suture loop alongthe component when the component is in an expanded configuration, 3) theplurality of suture loops aligned longitudinally along a longitudinalaxis of the stent graft when the stent graft is in a radiallyconstricted configuration, b) at least one ligature having a proximalend and a distal end, the at least one ligature extending through atleast some of the plurality of suture loops, i) whereby tension on theat least one ligature longitudinally aligns the suture loops along thelongitudinal axis of the component, thereby at least partially radiallyconstricting the stent graft.
 2. The stent graft system of claim 1,wherein each suture loop having a first end and a second end, both firstand second ends attached to the inner surface of the stent graft.
 3. Thestent graft system of claim 1, wherein each suture loop having a firstend and a second end, both first and second ends attached to the outersurface of the stent graft.
 4. The stent graft system of claim 1,wherein the suture loops extend around less than an entire circumferenceof the stent graft.
 5. The stent graft system of claim 1, wherein atleast a portion of the plurality of suture loops are each nested betweenan opening of struts of a stent of the plurality of stents.
 6. The stentgraft system of claim 1, wherein the component defines a fenestration.7. The stent graft system of claim 1, wherein each of the plurality ofsuture loops is a single loop of suture.
 8. The stent graft system ofclaim 1, wherein a majority of the plurality of suture loops are closerto a proximal end of the stent graft than a distal end of the stentgraft.
 9. The stent graft system of claim 1, wherein at least one of theplurality of suture loops is closer to a distal end of the stent graftthan to a proximal end of the stent graft.
 10. The stent graft system ofclaim 1, wherein the plurality of stents that are radially constrictedby the ligatures are radially self-expanding.
 11. The stent graft systemof claim 1, wherein the at least one ligature comprises a plurality ofligatures, a) a first ligature extending through a portion of theplurality of suture loops distributed about a proximal portion of thecomponent, b) a second ligature extending through a portion of theplurality of suture loops distributed about a distal portion of thecomponent, c) whereby tension of the first ligature independentlycontrols radial expansion of the plurality of stents along the proximalportion of the component, and d) whereby tension of the second ligatureindependently controls radial expansion of the plurality of stents alongthe distal portion of the component.
 12. A stent graft system,comprising: a) a stent graft that includes i) a component defining ahaving a longitudinally extending outer surface and a longitudinallyextending inner surface, the inner surface defining a lumen having alongitudinal axis; ii) a plurality of stents distributed longitudinallyalong the component; iii) a plurality of suture loops, a first sutureloop spaced both laterally and longitudinally relative to an adjacentsuture loop along a first stent of the plurality of stents, when thecomponent is in an expanded configuration; and b) at least one ligaturehaving a proximal end and a distal end, the at least one ligatureextending through the first suture loop and laterally through theadjacent suture loop, when the component is in an expandedconfiguration.
 13. The stent graft system of claim 12, wherein the firstsuture loop and adjacent suture loop align longitudinally along alongitudinal axis of the first stent when the first stent is in aradially constricted configuration.
 14. The stent graft system of claim12, wherein the first end and second end of the at least one ligaturealign longitudinally when the component is in a radially constrictedconfiguration.
 15. The stent graft system of claim 12, wherein tensionon the at least one ligature longitudinally aligns the suture loopsalong the longitudinal axis of the component, thereby at least partiallyradially constricting the stent graft.
 16. The stent graft system ofclaim 12, wherein the first stent includes struts joined at oppositeends to define distal and proximal apices, and the first suture loop andadjacent suture loop is nested between struts of the first stent. 17.The stent graft system of claim 12, wherein the plurality of stents thatare radially constricted by the ligatures are radially self-expanding.18. The stent graft system of claim 12, wherein the component defines afenestration.
 19. The stent graft system of claim 12, wherein each ofthe plurality of suture loops is a single loop of suture.
 20. The stentgraft system of claim 12, wherein the at least one ligature comprises aplurality of ligatures, a) a first ligature extending through a portionof the plurality of suture loops distributed about a proximal portion ofthe component, b) a second ligature extending through a portion of theplurality of suture loops distributed about a distal portion of thecomponent, c) whereby tension of the first ligature independentlycontrols radial expansion of the plurality of stents along the proximalportion of the component, and d) whereby tension of the second ligatureindependently controls radial expansion of the plurality of stents alongthe distal portion of the component.